1. Field of the Invention
This invention relates to a system and method for increasing the bandwidth efficiency and data transmission performance of radio frequency wireless, optical wireless and fiber-optics digital communication link without requiring an increase in the signal power.
2. Background Information
With the growth of internet, broadband connectivity has been considered the future of the global telecommunication industry. The increasing demands in running near real time applications in the web have exhausted most of licensed and unlicensed spectral bands previously allocated for commercial wireless, metro and long-hauled DWDM fiber-optics systems. The most cost effective solution of this problem is to dramatically improve the efficiency of transmitting information over the present spectrum allocation without requiring major changes in the existing telecommunication infrastructure.
The communication efficiency associated with transmitting information is known to be dependent upon the signal design, error correction code as well as the characteristics of the transmission medium. While the theories of high-speed digital communications in the time domain are known, there has been little progress to utilize additional dimensions in the spatial domain as information carriers. There was some advancement in recent years to exploit the spatial capacity by inserting additional antennas as in an antenna array. Each antenna would carry multiple temporal frequency channels.
One example is in the U.S. Pat. No. 614,471 of Raleigh et al that discloses an algorithm to process temporal frequency channels from multiple antennas in achieving orthogonal signal properties. This access technique is commonly known as orthogonal frequency division multiplexing (OFDM). Another example is in U.S. Pat. No. 6,285,720B1 of Martone that reveals the advantages in using an antenna array to sample a wavefield distorted by a wireless propagation channel. Details of array processing is disclosed in U.S. Pat. No. 6,317,411B1 of Whinnett et al, while Huang et al presents their ideas in using code division multiple access (CDMA) in wireless antenna array processing, in U.S. Pat. No. 6,301,293B1. These types of space-time system design gain some advantages in realizing temporal frequency diversity and some spatial path diversity through different antennas. However, they fail to exploit multiple spatial modes and they fall short of actually implementing spatial modulation in the transverse electric field as disclose in this present invention.
It is one object of the present invention to provide a system and method for increasing the spectral efficiency of a wireless and optical communication channel.
It is another object of the present invention to minimize the transmission errors by performing multiple iterative decoding on the received data.
Yet another object of the present invention is to increase code rate by transmitting redundant data through the spatial channels.
Still another object of the present invention is to mitigate errors induced by fading and scintillation using the interleaver that scrambles the combined spatial and temporal sequence.
Still another object of the present invention is to increase the coding gain by transmitting data sequence through the orthogonal polarization channels in a single mode system.
Still another object of the present invention is to increase the coding gain by transmitting data sequence through the orthogonal spatial channels in a multi-mode system.
Still another object of the present invention is to expand transmission capacity via spatial dimensions.
Still another object of the present invention is to increase throughput of a wireless radio frequency transmission system by using multiple and multifeed antennas.
Still another object of the present invention is to increase throughput of a wireless optical transmission system by using multiple and multimode antennas.
Still another object of the present invention is to increase throughput of a fiber optical transmission system by using multiple and multimode fibers.
Still another object of the present invention is to increase throughput of a wireless optical and fiber optical transmission system by using multiple wavelengths.
Still another object of the present invention is to increase spectral efficiency by varying the polarization states of the transmitting fields.
Still another object of the present invention is digital modulation of polarization states of transmitting fields by polarization phase shift keying.
Still another object of the present invention is digital modulation of polarization states of transmitting fields by polarization frequency shift keying.
Still another object of the present invention is digital modulation of polarization states of transmitting fields by polarization amplitude shift keying.
Still another object of the present invention is high level digital modulation of M polarization states of transmitting fields by M-ary polarization phase and amplitude modulation.
Still another object of the present invention is high level digital modulation of M polarization states of transmitting fields that constitute a spherical constellation.
Still another object of the present invention is analog modulation of polarization states of transmitting fields by polarization phase modulation.
Still another object of the present invention is analog modulation of polarization states of transmitting fields by polarization frequency modulation.
Still another object of the present invention is analog modulation of polarization states of transmitting fields by polarization amplitude modulation.